If you are installing a PVC home water system pipeline to a sewer main line made of clay pipe, a special coupling is required. In most cases, all sewer main lines owned by a city are already fitted with the proper y-fittings. All you need to do is connect the PVC pipe to these fittings. You should do this under the supervision of a certified plumbing and sewer expert from the city. You also must have the proper-sized PVC pipe to match the sewer connection.
Things You'll Need
Rubber sewer pipe gaskets
Fernco couplings PVC to clay sewer pipe connections
PVC pipe main line
Measure the diameter of the connector on the end of the sewer line. Make sure it is exactly the same size as the PVC pipe you are using. If not, you will need to size and buy an adapter to connect the pipes. One end must match the diameter of the sewer pipe connector; the other must match the diameter of your PVC pipe line.
Loosen the steel clamp using a large slot-head screw driver on one end of the Fernco coupler.
Slide the end of the coupler over the PVC pipe so there are 2 to 3 inches of coupler over the pipe walls. Using a large slot-head screwdriver, tighten the clamp.
Loosen the other clamp with a slot-head screwdriver. Slide it over the sewer pipe. Again, there needs to be at least 3 inches or more of coupler over the pipe walls.
Test the clamp tightness by inserting a torque wrench with slot-head into the clamp screw head and turning the wrench. It must be tightened to 60-inch pounds of torque.
Fernco couplers come in all shapes and sizes. Consult your city sewer department to find out which one to use for your location and pipe size.